Product Summary

A gearbox is a device which converts speed and torque, whereas a transmission is a type of gearbox that can be "shifted" to dynamically change the speed: torque ratio, such as in a vehicle. The most common use is in motor vehicles, where the transmission adapts the output of the internal combustion engine to the drive wheels. Such engines need to operate at a relatively high rotational speed, which is inappropriate for starting, stopping, and slower travel. The transmission reduces the higher engine speed to the slower wheel speed, increasing torque in the process. Transmissions are also used on pedal bicycles, fixed machines, and anywhere else rotational speed and torque needs to be adapted.
A valve gearbox is operable to rotate the valve member through the drive opening. The gearbox includes a casing including a mounting wall positioned adjacent the mounting surface of the valve body. At least one mounting hole is formed in the mounting wall and is disposed adjacent the mounting bore. At least one pin hole is formed in the mounting wall and receives the pin. A drive hole is formed in the mounting wall and communicates with the drive opening. At least one fastener extends through the mounting hole and engages the mounting bore to secure the casing to the mounting surface. The pin resists relative rotational movement of the casing and the valve body.